JP5058460B2 - LATHE WITH POLISHING DEVICE AND SHAFT WORK PROCESSING METHOD USING THE SAME - Google Patents

Description

The present invention relates to a lathe and a machining method using the lathe, and more particularly, a lathe with a polishing apparatus for removing a turning lead of a shaft-like workpiece having an oil seal fitting portion on an outer peripheral surface thereof by dry machining in the lathe and the same. It relates to a processing method.

  Various parts for automobiles including constant velocity joints are not limited to shaft-like parts having an oil seal fitting portion on the outer peripheral surface. Such a shaft-shaped part is generally formed by turning with a lathe, but the turning lead stitches may remain slightly rough in the oil seal fitting portion. If such a rough turning lead remains, oil may leak outside along the turning lead. For this reason, if the roughness of the turning lead is large, it must be removed. However, since it is actually difficult to determine the roughness, the oil seal fitting part is uniformly ground and finished. It has been removed.

  However, in the grinding process, a grinding fluid such as mineral oil is generally indispensable to prevent grinding burn. When the grinding fluid is used, the working environment is deteriorated due to the scattering of the fluid, and the cost of draining treatment is involved. In recent years, in order to solve the problem of such a grinding fluid, depending on the workpiece, there is a tendency to switch from a grinding process that requires a grinding fluid to a dry cutting process that does not require a grinding fluid. However, in the outer diameter part finishing process for shaft-shaped parts that have an oil seal fitting part on the outer peripheral surface, the turning lead stitches may inevitably remain rough, so the grinding process should be switched uniformly to the cutting process. It is difficult to dry completely.

The present invention has been invented in view of such circumstances, and its purpose is to remove the turning lead of a shaft-like workpiece having an oil seal fitting portion on its outer peripheral surface by a grinding method that does not require grinding fluid. An object is to provide a lathe with a polishing apparatus and a processing method using the lathe .

According to the first aspect of the present invention, there is provided a spindle head for rotationally driving a shaft-shaped workpiece having an oil seal fitting portion on its outer peripheral surface around the axis thereof, a tool turret, and a drive for moving the tool turret in the radial direction of the shaft-shaped workpiece. A mechanism, a slide base attached to the tool turret so as to be movable in the radial direction of the axial workpiece, and a rotary base attached to the slide base so as to be rotatable. An elastic grindstone that can freely move forward and backward, and a slide table that is moved back and forth with respect to the axis of the headstock relative to the tool turret, and the slide table is allowed to move backward with respect to the tool turret when a predetermined load or more is applied. possess a first drive means, in a state where the elastic grindstone is brought into contact with the oil seal fitting portion, is moved toward the tool turret by the drive mechanism to the shaft-like workpiece co The by said slide table and said elastic grindstone by the first drive means to polish while always retracted relative to the tool turret, be always abut against the oil seal fitting portion at a constant pressure the elastic grindstone It is characterized by.

According to a third aspect of the present invention, in the processing method using the first aspect of the invention, the tool turret is directed toward the shaft-like workpiece by the drive mechanism in a state where the elastic grindstone is in contact with the oil seal fitting portion. The elastic grindstone is always brought into contact with the oil seal fitting portion with a constant pressure by moving the slide base and the elastic grindstone backward with respect to the tool turret by the first driving means while moving. And

According to a fourth aspect of the present invention, in the machining method described above, an oil seal fitting portion on an outer peripheral surface of the shaft-like workpiece is formed by a tool attached to the tool turret while the shaft-like workpiece is rotationally driven around the axis by the headstock. a step of cutting the steps of: said tool turret is rotated Ru to face the elastic grindstone to the oil seal fitting portion of the shaft-like workpiece, while rotating the shaft-like workpiece about its axis by said headstock , the elastic grindstone, characterized in that a step of polishing the oil seal fitting portion is brought into contact with the oil seal fitting portion.

 Here, the elastic grindstone is, for example, a diamond particle, an aluminum oxide particle, a cerium oxide particle, or a soft resin granule such as polyvinyl alcohol, polyurethane, or a porous fluororesin (for example, polytetrafluoroethylene) as a binder. It is manufactured by mixing, pressing, and baking a mixture of abrasive grains such as silicon oxide. The shape of the rotating whetstone is a ring-shaped elastic whetstone fixed to a disk-shaped whetstone base, a disk-shaped elastic whetstone fixed to a disk-shaped whetstone base, and a cylindrical elastic whetstone fixed to the outer periphery of the disk-shaped whetstone base Is possible. The end surface of the elastic grindstone may be a polished surface, and the peripheral surface of the elastic grindstone may be a polished surface.

 Since the present invention uses an elastic grindstone, the elastic body holding the abrasive grains acts as a spring, so that the convex abrasive grains move elastically in the same direction, and the irregularities of the grindstone are averaged. . Accordingly, since the load applied between the workpiece and the elastic grindstone is reduced, it is possible to prevent the abrasive grains from causing chipping, and polishing without chipping that causes stress concentration due to heat and a decrease in bending strength can be performed. In addition, since the load is small, the rotation speed of the grindstone can be reduced, so that the amount of heat generated by the workpiece and the grindstone is reduced, and there is no need to use coolant. For this reason, it is possible to perform dry polishing (polishing without using a liquid such as water) suitable for polishing a workpiece having a processed part that is not suitable for adhesion of dust, water and the like.

 According to the present invention, since an elastic grindstone is used, it is possible to remove the turning leads in a dry manner without causing grinding burn, in which case the generation of dust is extremely small, and for the grinding fluid. Since no equipment is required, the equipment cost and electricity charge for them can be reduced. Further, it is possible to solve the problem of working environment deterioration and drainage treatment due to scattering of the grinding fluid.

 In addition, it is possible to easily incorporate a polishing machine into a general lathe, which enables machining of only the hardened steel cutting finish in the lathe, or turning with an elastic grindstone after the hardened steel cutting finish. Any of the processing to remove the eyes can be freely selected. For example, even in the case of a shaft-like workpiece used for a constant velocity joint of the same type, whether or not turning leads need to be removed may differ depending on the model number. Regardless of this, the shaft-like workpiece can be machined on the same line, and the production cost can be reduced by sharing the line.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. In FIGS. 1 and 2, reference numeral 1 denotes a spindle head of the lathe, 2 denotes a three-claw chuck attached to the spindle 1 a of the spindle head 1, and 3 denotes a tailstock that faces the spindle head 1. In addition, the bed etc. to which the tailstock 3 is attached are not shown.

 In this embodiment, the outer joint member 4 of a sliding type constant velocity universal joint is illustrated as a shaft-shaped work which has an oil seal fitting part in an outer peripheral surface. The outer joint member 4 has a cup shape with a shaft. The tip of the chuck 2 is fitted to the inner diameter of the cup portion 4a, and the outer diameter of the cup portion 4a is held by the chuck claws 2a. On the other hand, the center 3 a of the tailstock 3 is abutted against the center of the tip end of the shaft portion 4 b on the opposite side of the outer joint member 4. Thus, the outer joint member 4 is centered.

 A regular octagonal plate-shaped tool turret 5 that can be moved up and down by a lift drive mechanism (not shown) is disposed above the lathe bed. A rotation shaft (not shown) for indexing rotation parallel to the main shaft 1 a is connected to the center of the tool turret 5. The tool turret 5 is capable of attaching up to eight types of tools around the tool turret 5 at the same time. As a result, the tool turret 5 is indexed and rotated to switch to a desired tool, and necessary work is performed on the workpiece rotated by the spindle 1a.

 A square substrate 6 is bolted to the front surface of the tool turret 5. As shown in the figure, a plurality of linear guides 7 in the vertical direction are arranged in parallel on the substrate 6. A slide base 8 is slidably attached to these linear motion guides 7. The slide table 8 is connected to an air cylinder (first driving means) 9 attached to the end of the substrate 6 and moves up and down by the expansion and contraction of the air cylinder 9. The position immediately before the last withdrawal of the slide base 8 is detected by a sensor (not shown). A relief valve is attached to the driving air circuit of the air cylinder 9, and when a load exceeding a predetermined value is applied to the piston 9a of the air cylinder 9, air is allowed to escape from the relief valve and the piston 9a is allowed to be shortened. The slide table 8 is provided with a brushless motor (second drive means) 10 having a rotation shaft 10 a parallel to the main shaft 1 a and a spindle 11 parallel to the rotation shaft 10 a of the motor 10. The bearing 12 of the spindle 11 is fixed to the slide table 8.

 A belt 15 is stretched between a small pulley 13 attached to one end of the spindle 11 and a large pulley 14 attached to the rotating shaft 10 a of the motor 10. The center of the elastic grinding wheel 16 is attached to the other end of the spindle 11. The elastic grinding wheel 16 is attached to the slide base 8 at a height where the center of the elastic grinding wheel 16 coincides with the lathe spindle 1a with the air cylinder 9 extended to the maximum at the index rotation position of the tool turret 5. It is done.

The lathe with a polishing apparatus is configured as described above, and the turning and grinding of the outer joint member 4 that is a shaft-like workpiece by the lathe with the polishing apparatus is performed as follows.

 First, the outer joint member 4 is attached between the main shaft 1 a and the center 3 a, and the outer diameter of the outer joint member 4 is gripped by the chuck 2. In this state, the outer joint member 4 is rotated by rotating the main shaft 1a.

 When turning the outer diameter surface of the outer joint member 4, the tool turret 5 is indexed and rotated so that the cutting edge of the desired cutting tool 17 faces downward toward the outer joint member 4. In this state, the tool turret 5 is moved downward to abut the cutting edge of the cutting tool 17 against the outer diameter surface of the outer joint member 4 to turn the outer diameter surface.

 Next, when removing, for example, the turning lead of the oil seal fitting portion 4c of the outer joint member 4 formed by turning, the tool turret 5 is indexed and rotated to move the elastic grinding wheel 16 to the lowest limit position. The air cylinder 9 is extended to the maximum. When the air cylinder 9 is extended to the maximum extent, the slide base 8 is at the most advanced position with respect to the substrate 6 or the tool turret 5. In this state, the tool turret 5 is moved down at a low speed, and the lower end of the elastic grinding wheel 16 is brought into contact with the oil seal fitting portion 4 c of the outer joint member 4. Thereby, polishing of the oil seal fitting portion 4c starts.

 The tool turret 5 is continuously moved down at a constant speed even during the polishing of the oil seal fitting portion 4c. At this time, the piston 9a of the air cylinder 9 is pushed into the air cylinder main body by an amount equal to the downward movement amount of the tool turret 5. Excess air in the air cylinder body is released from the relief valve. As a result, the elastic grinding wheel 16 always abuts against the outer diameter surface of the outer joint member 4 at a constant optimum pressure, and a good polishing action is obtained.

 Immediately before the piston 9a of the air cylinder 9 is shortened and the slide table 8 reaches the last retracted position, the downward movement of the tool turret 5 is stopped based on a signal from a sensor that detects the position immediately before the last slide of the slide table 8. After this stop state is continued for a certain period of time, the air cylinder 9 is retracted by the last retreat allowance, and the elastic grinding wheel 16 is separated from the outer joint member 4. Thereafter, the outer joint member 4 is removed from the main shaft 1a, and the polishing step is completed. In this polishing process, it was confirmed that the turning leads were completely removed and a high-quality finished surface equivalent to normal grinding was obtained.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various deformation | transformation is possible in the range which does not deviate from the summary of this invention.

The front view of the lathe with a polisher concerning the present invention. The side view of the lathe with a polisher concerning the present invention.

Explanation of symbols

1 Main shaft base 1a Main shaft 2 Chuck 2a Chuck claw 3 Tailstock 3a Center 4 Outer joint member (shaft workpiece)
4a Cup portion 4b Shaft portion 4c Oil seal fitting portion 5 Tool turret 6 Substrate 7 Linear motion guide 8 Slide base 9 Air cylinder 9a Piston 10 Brushless motor 10a Rotating shaft 11 Spindle 12 Bearing 13 Small pulley 14 Large pulley 15 Belt 16 Elastic grindstone Wheel 17 bytes

Claims (4)

A spindle stock for rotating a shaft-like workpiece having an oil seal fitting portion on its outer peripheral surface around its axis, a tool turret, a drive mechanism for moving the tool turret in the radial direction of the shaft-like workpiece, and the tool turret A slide base that is movably mounted in the radial direction of the shaft-shaped workpiece, and an elastic grindstone that is rotatably mounted on the slide table and is movable back and forth in the radial direction of the shaft-shaped workpiece with respect to the oil seal fitting portion. , said slide table to move back and forth facing the headstock axis relative to the tool turret, have a first drive means for permitting retraction with respect to the slide base of the tool turret and the predetermined or more load is applied ,
While the elastic grindstone is in contact with the oil seal fitting portion, the drive mechanism moves the tool turret toward the shaft-shaped workpiece, and the first drive means moves the slide base and the elastic grindstone to the A lathe with a polishing device that always makes the elastic grindstone contact the oil seal fitting portion with a constant pressure by polishing while always retracting the tool turret .   The lathe with a polishing apparatus according to claim 1, wherein the elastic grindstone is an elastic grindstone wheel, and has second drive means for rotating the elastic grindstone wheel. A method for machining a shaft-shaped workpiece using the lathe with a polishing apparatus according to claim 1 or 2,
Said elastic grindstone being in contact with the oil seal fitting portion, Rutotomoni is moved toward the tool turret shaft-shaped workpiece by said driving mechanism, said slide base by said first drive means and said elastic grindstone A method of machining a shaft-shaped workpiece, wherein polishing is performed while always retreating the tool turret so that the elastic grindstone is always brought into contact with the oil seal fitting portion with a constant pressure.   Cutting the oil seal fitting portion of the outer peripheral surface of the shaft-like workpiece with a tool attached to the tool turret while rotating the shaft-like workpiece around its axis by the headstock, and rotating the tool turret The elastic grindstone is brought into contact with the oil seal fitting portion of the shaft-like workpiece, and the elastic grindstone is brought into contact with the oil seal fitting portion while the shaft-like workpiece is rotationally driven around the axis by the headstock. The method for machining a shaft-like workpiece according to claim 3, further comprising the step of polishing the oil seal fitting portion.

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